Handguns

Glock pistols

The standard issue to the Baltimore Police Department is the Glock 17 and the Glock 19, which at the time was standard issue in real life. Detectives appear to switch between Glock 17s and Glock 19s throughout the series. Glocks are carried by Detective John Munch (Richard Belzer), Detective Beau Felton (Daniel Baldwin), Detective Meldrick Lewis (Clark Johnson), Detective Mike Kellerman (Reed Diamond), Detective Tim Bayliss (Kyle Secor), Detective Frank Pembleton (Andre Braugher), Detective Stu Gharty (Peter Gerety), Detective Laura Ballard (Callie Thorne), Detective Paul Falsone (Jon Seda), and Captain Megan Russert (Isabella Hofmann), as well as most of the lesser officers and detectives. BPD officers nowadays use Glock 22s in real life. Lieutenant Al Giardello (Yaphet Kotto) briefly uses one in the episode "Fallen Heroes". In the episode "Fallen Heroes", Junior Bunk (Mekhi Phifer) takes a detective's Glock from his desk and uses it to kill three police officers in the Homicide Squad room. He then continues firing at other officers and detectives before being shot and killed. Of an interesting note, while most detectives fire their weapon using a two-handed grip, Detective Frank Pembleton often fires his Glock one-handed. Detectives Munch, Felton, and Falsone carry their Glocks in shoulder holsters, while all other detectives carry them in paddle holsters.

Taurus PT92CS

Astra Terminator

An Astra Terminator appears in the episode "Secrets", and is misidentified as a ".44 Caliber Smith & Wesson". The cylinder release latch and the grips, however, ID it as an Astra and not a Smith & Wesson.

Astra Terminator .44 Magnum, left side

Beretta 92FS

A Beretta 92FS appear in the episodes "Scene of the Crime" (S04E18), "The Damage Done" (S04E20) and "Fallen Heroes: Part 1".

Beretta 92FS - 9x19mm

A murder victim with a Beretta in his hand in "Scene of the Crime" (S04E18).

Forrest Pendell (Akil Wingate) shoots a truck drive with what appears to be a Beretta 92FS in "The Damage Done" (S04E20).

A gunman fires upon Felton, Howard, Bolander and Munch in "The City That Bleeds." (S03E12)

Even though the gunman is eventually revealed to be Gordon Pratt, played by Steve Buscemi, it is unlikely that this particular gunman was played by Buscemi, who did not appear until two episodes later.

Taurus PT92

A thug uses a stainlessTaurus PT92 in the episode "Fallen Heroes: Part 2".

Heckler & Koch MP5K-PDW

Heckler & Koch MP5K

In the episode "Hostage Part 1 & Part 2", genuine Heckler & Koch MP5Ks appear in the hands of QRT Officers.

Heckler & Koch MP5K - version with SEF Plastic Trigger Pack - 9x19mm. This is a very well worn Motion picture weapon

Rifles/Assault Rifles

Remington 700

In the episode "Hostage", QRT Snipers are seen carrying Remington 700 rifles.

Remington 700PSS with Harris bipod, in .300 Win Mag

Heckler & Koch HK91 (mocked up as SR9)

William Mariner (Andrew Parks) uses a Heckler & Koch HK91 mocked up as an H&K SR9 during his killing spree in "Sniper (Part 1)" (S04E08). During the investigation, Homicide detectives determined that they were looking for an "HK" in ".308." Given that Mariner was an insurance executive who was a former military sharpshooter, it would make sense for him to have such an expensive rifle.

HK91-A2 Rifle with Standard Stock Note lack of third position for automatic fire - 7.62x51mm NATO

H&K SR9(TC) rifle with tropical forearm and bipod - 7.62x51mm. The TC version has the PSG buttstock as well as the trigger pack.

M1 Carbine

Alex Robey (David Eigenberg) uses a scoped M1 Carbine during his copycat shooting spree in "Sniper (Part 2)" (S04E09). Detectives incorrectly state that the rifle is chamber in ".308" like the faux SR9 of the first sniper. A ballistics expert later identifies it as a "M1A Carbine," which is even more confusing.